This is a mod that adds 4 new music discs to the game: "minimal," "depado," "krank," and "phlips," all of which were produced by C418 and released under CC-By 3.0 licenses. "minimal" and "depado" come from C418's album circle, and "krank" and "phlips" come from zweitonegoismus.
This mod requires Mineclone 2, more specifically mcl_jukebox, to run. It will likely also work with Mineclone 5, but this hasn't been tested.